US20100182522A1

US20100182522A1 - Array substrate and method of manufacturing the same

Info

Publication number: US20100182522A1
Application number: US12/364,858
Authority: US
Inventors: Hwa-Sung Woo; Joo-nyung Jang; Cheol Shin; Yoon-Sung Um; Mi-Jeong Song
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Display Co Ltd
Priority date: 2009-01-16
Filing date: 2009-02-03
Publication date: 2010-07-22
Also published as: KR20100084451A; US8169559B2; EP2209042B1; EP2209042A1; KR101552543B1; EP2431803A1; EP2431803B1

Abstract

In an array substrate and a method of manufacturing the array substrate, an array substrate includes a first switching element, a second switching element, a third switching element and a fourth switching element. The first switching element is electrically connected to a first data line. The second switching element is electrically connected to a second data line adjacent to the first data line. The third switching element is electrically connected to a data power line interposed between the first and second data lines. The fourth switching element is electrically connected to a gate power line receiving a voltage having different polarity from a voltage applied to the data power line. Therefore, light transmittance, opening ratio and display quality are improved

Description

PRIORITY STATEMENT

This application claims priority under 35 USC §119 to Korean Patent Application No. 2009-3560, filed on Jan. 16, 2009 in the Korean Intellectual Property Office (KIPO), the contents of which are herein incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
Example embodiments of the present invention relate to an array substrate and a method of manufacturing the array substrate. More particularly, example embodiments of the present invention relate to an array substrate capable of light transmittance, opening ratio and optical characteristics and a method of manufacturing the array substrate.
2. Description of the Related Art
A liquid crystal display (LCD) device that is one of flat panel display devices has been widely used in various fields. The LCD device includes an array substrate having a pixel electrode and an opposite substrate having a common electrode to form an electric field. Also, the LCD device further includes a liquid crystal layer interposed between the array substrate and the opposite substrate.
When a voltage difference is applied to the pixel electrode and the common electrode, an electric field is formed between the pixel electrode and the common electrode. Liquid crystals of the liquid crystal layer vary arrangement in response to the electric field applied thereto, and thus light transmittance of the liquid crystal layer is changed by controlling polarization of an incident light thereby displaying an image.
The LCD device also controls a switching element electrically connected to each of the pixel electrodes, and a plurality of signal lines such as a gate line and a data line to apply the voltage to the pixel electrode.
The LCD device receives an input image signal fron an externally provided graphic controller. The input image signal includes luminance information of the pixels.
Each of the pixels receives a data voltage corresponding to the luminance information. Each of pixels of the LCD device displays an image of a luminance corresponding to a gray-scale of the image signal based on the pixel voltage difference between the data voltage applied to the pixel and a vommon voltage applied to the common electrode. The range of the pixel voltage difference applied to the pixel and common electrodes is predetermined by a driving part of the LCD device.
The driving part of the LCD device may be directly mounted on the array substrate as a chip type, or may be attached to the array substrate using a flexible circuit film. The integrated circuit chip is expensive in manufacturing the LCD device.
In order to reduce the manufacturing cost, the range of the pixel voltage difference is restricted. Also, parasite capacitance may be formed between the data lines, so that image display quality of the LCD device may be deteriorated.
In addition, when the number of the gate and data lines on the array substrate is increased, opening ratio of the display device is decreased.

SUMMARY OF THE INVENTION

Example embodiments of the present invention provide an array substrate capable of light transmittance, opening ratio and optical characteristics.
Example embodiments of the present invention provide a method of manufacturing the above-mentioned array substrate.
According to one aspect of the present invention, an array substrate includes a first switching element, a second switching element, a third switching element and a fourth switching element. The first switching element is electrically connected to a first data line. The second switching element is electrically connected to a second data line adjacent to the first data line. The third switching element is electrically connected to a data power line interposed between the first and second data lines. The fourth switching element is electrically connected to a gate power line receiving a voltage having different polarity from a voltage applied to the data power line.
Voltages having opposite polarities may be applied to the first and second data lines, respectively.
The array substrate may further include a first gate line substantially parallel with the gate power line, a first pixel electrode electrically connected to the first switching element, a second pixel electrode electrically connected to the second switching element, a first common electrode electrically connected to the third switching element, and a second common electrode electrically connected to the fourth switching element. The first pixel electrode and the first common electrode may be disposed in a first pixel region, and the second pixel electrode and the second common electrode may be disposed in a second pixel region adjacent to the first pixel region along the first gate line.
The array substrate may further include a fifth switching element electrically connected to the first data line, a sixth switching element electrically connected to the second data line, a seventh switching element electrically connected to the gate power line, and an eighth switching element electrically connected to the data power line.
The array substrate may further include a first gate line extended in a direction substantantially parallel with the gate power line, a third pixel electrode electrically connected to the fifth switching element, a fourth pixel electrode electrically connected to the sixth switching element, a third common electrode electrically connected to the seventh switching element, and a fourth common electrode electrically connected to the eighth switching element. The third pixel electrode and the third common electrode may be disposed in a third pixel region adjacent to the first pixel region along the first data line, and the fourth pixel electrode and the fourth common electrode may be disposed in a fourth pixel region adjacent to the second pixel region along the first data line.
The array substrate may further include a first gate line extended in a direction substantially parallel with the gate power line, and a second gate line adjacent to the first gate line. The first, second, third and fourth switching elements may be electrically connected to the first gate line, and the fifth, sixth, seventh and eighth switching elements may be electrically connected to the second gate line.
Each of the first and second pixel electrodes and the first and second common electrodes may include a plurality of branching parts. The branching part of the first pixel electrode may alternate with the branching part of the first common electrode, and the brahcning part of the second pixel electrode may alternate with the branching part of the second common electrode.
According to another aspect of the present invention, there is provided a method of manufacturing an array substrate as follows. A gate line and a gate power line substantially parallel with the gate line are formed. A first data line, a second data line and a data power line may be interposed between the first data line and the second data line. A first switching element electrically connected to the first data line and the gate line, a second switching element electrically connected to the second data line and the gate line, a third switching element electrically connected to the data power line and the gate line, and a fourth switching element electrically connected to the gate power line and the gate line are formed. The gate power line receives a voltage having different polarity from a voltage applied to the data power line.
A first pixel electrode electrically connected to the first switching element, a second pixel electrode electrically connected to the second switching element, a first common electrode electrically connected to the third switching element and a second common electrode electrically connected to the fourth switching element may further be formed. The first pixel electrode and the first common electrode may be formed in a first pixel region, and the second pixel electrode and the second common electrode may be formed in a second pixel region adjacent to the first pixel region along the gate line.
The first, second, third and fourth switching elements may be formed by forming a fifth switching element electrically connected to the first data line, a sixth switching element electrically connected to the second data line, a seventh switching element electrically connected to the gate power line, and an eighth switching element electrically connected to the data power line.
According to still another aspect of the present invention, an array substrate includes a first pixel electrode, a second pixel electrode, a first common electrode and a second common electrode. The first pixel electrode is overlapped with first and second power lines extended along a gate line. The first and second power lines receive voltages having different polarities, respectively. The first pixel electrode is electrically connected to a first data line. The second pixel electrode is overlapped with the first and second power lines. The second pixel electrode is electrically connected to a second data line receiving a voltage having an opposite polarity to a voltage applied to the first data line. The first common electrode is overlapped with the first and second power lines, and is electrically connected to the first power line. The second common electrode is overlapped with the first and second power lines, and is electrically connected to the second power line.
A capacitance of each of first storage capacitors formed by overlapping the first and second pixel electrodes and the first and second common electrodes with the first power line may be substantially the same as a capacitance of each of second storae capacitors formed by overlapping the first and second pixel electrodes and the first and second common electrodes with the second power line.
The first common electrode may be partially overlapped with the first and second data lines.
The array substrate may further include a third data line adjacent to the second data line. The second common electrode may be partially overlapped with the second and third data lines, and the first and second common electrodes may be overlapped with first and second regions of the second data line, respectively. The first region may have substantially the same size as the second region. The first and second pixel electrodes and the first and second common electrodes may form a V-shape.
The first and second pixel electrodes may include a plurality of first bending branches, and the first and second common electrodes comprise a plurality of second bending branches. The first bending branches of the first pixel electrode may alternate the second bending branches of the first common electrode, and the first bending branches of the second pixel electrode may alternate the second bending branches of the second common electrode. A distance between adjacent first and second bending branches adjacent to the first data line or the third data line may be greater than a distance between adjacent first and second bending branches adjacent to a center between the first and second data lines and a center between the second and third data lines.
According to further still another aspect of the present invention, a method of manufacturing an array substrate is provided as follows. A gate line, a first power line and a second power line are formed. The gate line and the first and second power lines are substantially parallel with each other. A first data line and a second data line are adjacent to the first data line. The second data line receives a voltage having opposite polarity to a voltage applied to the first data line. The first and second data lines are substantially parallel with each other. A first pixel electrode electrically connected to the first data line, a second pixel electrode electrically connected to the second data line, a first common electrode electrically connected to the first power line and a second common electrode electrically connected to the second power line are formed. The first and second pixel electrodes and the first and second common electrodes are overlapped with the first and second power lines.
According to further still another aspect of the present invention, an array substrate includes a pixel electrode and a common electrode. The pixel electrode is electrically connected to a first data line. The common electrode is electrically connected to a second data line receiving a voltage having opposite polarity to a voltage applied to the first data line. The common electrode is overlapped with the first and second data lines and being adjacent to the first data line.
An overlapped area between the common electrode and the first data line may be substantially the same as an overlapped area between the common electrode and the second data line.
According to further still another aspect of the present invention, a method of manufacturing an array substrate is provided as follows. A first data line and a second data line adjacent to the first data line are formed. The second data line receives a voltage having opposite polarity to a voltage applied to the first data line. A pixel electrode electrically connected to the first data line and a common electrode electrically connected to the second data line are formed. The pixel electrode and the common electrode are overlapped with the first and second data lines.
According to some example embodiments of the present invention, the range of the pixel voltage difference is increased by the power lines receiving the various voltages, so that light transmittance of the array substrate may be increased.
Also, the storage capacitors are formed using the power lines, so that opening ratio of the array substrate is increased.
In addition, a parasite capacitor that may be generated in the data lines by overlapping between the data lines and the pixel electrodes receiving different voltages may be prevented, so that image display quality of the array substrate may be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detailed example embodiments thereof with reference to the accompanying drawings.

FIG. 1 is a plan view illustrating illustrating a liquid crystal display (LCD) device in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectinoal view taken along a line I-I′ shown in FIG. 1;

FIG. 3 is a cross-sectinoal view taken along a line II-II′ shown in FIG. 1;

FIG. 4 is an equivalent circuit diagram illustrating the LCD device shown in FIG. 1;

FIG. 5 is a plan view illustrating an LCD device in accordance with another embodiment of the present invention;

FIG. 6 is a cross-sectinoal view taken along a line III-III′ shown in FIG. 5;

FIG. 7 is a cross-sectional view taken along a line IV-IV′ shown in FIG. 5;

FIG. 8 is an equivalent circuit diagram illustrating the LCD device shown in FIG. 5;

FIG. 9 is a plan view illustrating an LCD device in accordance with still another embodiment of the present invention;

FIG. 10 is a plan view illustrating an LCD device in accordance with further still another embodiment of the present invention;

FIG. 11 is an equivalent circuit diagram illustrating the LCD device shown in FIG, 10; and

FIG. 12 is a plan view illustrating an LCD device in accordance with further still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity.
It will be understood that when an element or layer is referred to as being “on,” “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above to and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Example embodiments of the invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized example embodiments (and intermediate structures) of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present invention.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings.
FIG. 1 is a plan view illustrating illustrating a liquid crystal display (LCD)) device in accordance with one embodiment of the present invention. FIG. 2 is a cross-sectinoal view taken along a line I-I′ shown in FIG. 1. FIG. 3 is a cross-sectinoal view taken along a line II-II′ shown in FIG 1.
Referring to FIGS. 1 to 3, the LCD device includes an array substrate 100, an opposite substrate 200 and a liquid crystal layer 300. In FIG. 1, a first pixel PX(n,n) and a second pixel PX(n,n+1) of the LCD device are illustrated.
The array substrate 100 includes a lower base substrate 110. A pixel region is defined in the lower base substrate 110.
The lower base substrate 110 has a plate shape. A transparent material that may be used for the lower base substrate 110 may include glass, quartz, synthetic resin, etc. These may be used alone or in a combination thereof.
A gate metal layer is formed on the lower base substrate 110. The gate metal layer may include a gate line 121, agate power line 125 and a storage line 131.
The gate line 121 is extended in a longitudinal direction to transmit a gate signal. Each of the gate lines 121 includes a first gate electrode 124 a, a second gate electrode 124 b, a third gate electrode 124 c and a fourth gate electrode 124 d that are upwardly protruded. The first and third gate electrodes 124 a and 124 c correspond to the first pixel PX(n,n). The second and fourth gate electrodes 124 b and 124 d correspond to the second pixel PX(n,n+1).
The storage line 131 receives a voltage such as a common voltage, and is extended in the longitudinal direction. Each of the storage lines 131 is interposed between two adjacent gate lines 121, and is adjacent to a lower gate line 121 of the two adjacent gate lines 121. The storage line 131 includes a first storage electrode 133 a and a second storage electrode 133 b. The first storage electrode 133 a corresponds to the first pixel PX(n,n), and the second storage electrode 133 b corresponds to the second pixel PX(n,n+1).
The gate power line 125 transmits a power voltage or a ground voltage in each frame. The gate power line 125 may be extended in the longitudinal direction, and each of the gate power line 125 includes a gate power line 127 upwardly protruded.
Each of the first and second storage electrodes 133 a and 133 b has a rectangular shape having two chamfered corners adjacent to a lower side. Alternatively, each of the first and second storage electrodes 133 a and 133 b may have various shapes and various arrangements.
The gate insulating layer 140 is formed on the lower base substrate 110 to cover the gate line 121, the first, second, third and fourth gate electrodes 124 a, 124 b, 124 c and 124 d, the storage line 131 and the first and second storage electrodes 133 a and 133 b.
A first semiconductor layer 154 a, a second semicnodcutor layer 154 b, a third semiconductor layer 154 c and a fourth semiconductor layer 154 d are formed on the gate insulating layer 140. The first, second, third and fourth semiconductor layers 154 a, 154 b, 154 c and 154 d may include hydrogenated amorphous silicon, polycrystalline silicon, etc. The first, second, third and fourth semiconductor layers 154 a, 154 b, 154 c and 154 d are formed on the first, second, third and fourth gate electrodes 124 a, 124 b, 124 c and 124 d, respectively.
Two first ohmic contact layers 163 a and 165 a are formed on the first semiconductor layers 154 a. Two second ohmic contact layers 163 b and 165 b are formed on the second semiconductor layers 154 b. Two third ohmic contact layers 163 c and 165 c are formed on the third semiconductor layers 154 c. Two fourth ohmic contact layers 163 d and 165 d are formed on the fourth semiconductor layers 154 d. The first to fourth ohmic contact layers 163 a, 163 b, 163 c, 163 d, 165 a, 165 b, 165 c and 165 d may include n+ hydrogenated amorphous silicon that is implanted by n type impurities at a high concentration, silicide, etc.
A data metal layer including a first data line 171 a, a second data line 171 b, a data power line 171 c, a first drain electrode 175 a, a second drain electrode 175 b, a third drain electrode 175 c and a fourth drain electrode 175 d is formed on the first to fourth ohmic contact layers 163 a, 163 b, 163 c, 163 d, 165 a, 165 b, 165 c and 165 d and the gate insulating layer 140.
The first and second data lines 171 a and 171 b transmit data signals. The data power line 171 c transmits a driving voltage or a ground voltage by a frame. When the driving voltage is applied to the data power line 171 c, the ground voltage may be applied to the gate power line 125. When the ground voltage is applied to the data power line 171 c, the driving voltage is applied to the gate power line 125.
The first and second data lines 171 a and 171 b and the data power line 171 c are extended in a horizontal direction corssing the gate line 121 and the storage line 131. The first and second data lines 171 a and 171 b and the data power line 171 c include a first source electrode 173 a, a second source electrode 173 b and a third source electrode 173 c. The first, second and third source electrodes 173 a, 173 b and 173 c have U-shape bent toward the first, second and third gate electrodes 124 a, 124 b and 124 c, respectively. The fourth source electrode 173 d that has a U-shape bent toward the fourth gate electrode 124 d is extended toward an upper portion of the gate power electrode 127 to be electrically connected to the gate power electrode 127.
An end of a rod shape of each of the first, second, third and fourth drain electrodes 175 a, 175 b, 175 c and 175 d faces each of the first, second, third and fourth source electrodes 173 a, 173 b, 173 c and 173 d, and is surrounded by each of the first, second, third and fourth Source electrodes 173 a, 173 b, 173 c and 173 d.
A first contact electrode 177 a connected to the first drain electrode 175 a is overlapped with a left half of the first storage electrode 133 a, and a second contact electrode 177 b connected to the second drain electrode 175 b is overlapped with a right half of the second storage electrode 133 b.
A third contact electrode 177 c connected to the third drain electrode 175 c is overlapped with a right half of the first storage electrode 133 a, and a fourth contact electrode 177 d connected to the fourth drain electrode 175 d is overlapped with a left half of the second storage electrode 133 b.
The first gate electrode 124 a, the first source electrode 173 a, the first drain electrode 175 a and the first semiconductor layer 154 a form a first switching element Qa. The second gate electrode 124 b, the second source electrode 173 b, the second drain electrode 175 b and the second semiconductor layer 154 b form a second switching element Qb. The third gate electrode 124 c, the third source electrode 173 c, the third drain electrode 175 c and the third semiconductor layer 154 c form a third switching element Qc. The fourth gate electrode 124 d, the fourth source electrode 173 d, the fourth drain electrode 175 d and the fourth semiconductor layer 154 d form a fourth switching element Qd.
A channel of the first switching element Qa is formd in the first semiconductor layer 154 a between the first source electrode 173 a and the first drain electrode 175 a. A channel of the second switching element Qb is formd in the second semiconductor layer 154 b between the second source electrode 173 b and the second drain electrode 175 b. A channel of the third switching element Qc is formd in the third semiconductor layer 154 c between the third source electrode 173 c and the third drain electrode 175 c. A channel of the fourth switching element Qd is formd in the fourth semiconductor layer 154 d between the fourth source electrode 173 d and the fourth drain electrode 175 d.
A first one 163 a of the two first ohmic contact layers 163 a and 165 a is interposed between the first semiconductor layer 154 a and the first source electrode 173 a to decrease contact resistance between the first semiconductor layer 154 a and the first source electrode 173 a, and a second one 165 a of the two first ohmic contact layers 163 a and 165 a is interposed between the first semiconductor layer 154 a and the first drain electrode 175 a to decrease contact resistance between the first semiconductor layer 154 a and the first drain electrode 175 a. A first one 163 b of the two second ohmic contact layers 163 b and 165 b is interposed between the second semiconductor layer 154 b and the second source electrode 173 b to decrease contact resistance between the second semiconductor layer 154 b and the second source electrode 173 b, and a second one 165 b of the two second ohmic contact layers 163 b and 165 b is interposed between the second semiconductor layer 154 b and the second drain electrode 175 b to decrease contact resistance between the second semiconductor layer 154 b and the second drain electrode 175 b. A first one 163 c of the two third ohmic contact layers 163 c and 165 c is interposed between the third semiconductor layer 154 c and the third source electrode 173 c to decrease contact resistance between the third semiconductor layer 154 c and the third source electrode 173 c, and a second one 165 c of the two third ohmic contact layers 163 c and 165 c is interposed between the third semiconductor layer 154 c and the third drain electrode 175 c to decrease contact resistance between the third semiconductor layer 154 c and the third drain electrode 175 c. A first one 163 d of the two fourth ohmic contact layers 163 d and 165 d is interposed between the fourth semiconductor layer 154 d and the fourth source electrode 173 d to decrease contact resistance between the fourth semiconductor layer 154 d and the fourth source electrode 173 d, and a second one 165 d of the two fourth ohmic contact layers 163 d and 165 d is interposed between the fourth semiconductor layer 154 d and the to fourth drain electrode 175 d to decrease contact resistance between the fourth semiconductor layer 154 d and the fourth drain electrode 175 d.
The first switching element Qa is electrically conneted to the first data line 171 a. The third switching element Qc is electrically conneted to the data power line 171 c. The first and third switching elements Qa and Qc are formed in the first pixel PX(n,n).
The second switching element Qb is electrically conneted to the second data line 171 b. The fourth switching element Qd is electrically conneted to the gate power line 125. The second and fourth switching elements Qb and Qd are formed in the second pixel PX(n,n+1).
Voltages having opposite levels are applied to the first and second data lines 171 a and 171 b, respectively. Voltages having opposite levels are applied to the data power line 171 c and the gate power line 125.
A gate contact hole 129 is formed on the gate power electrode 127 through the gate insulating layer 140. The fourth source electrode 173 d is connected to the gate power line 125 through the gate contact hole 129.
The data insulating layer 180 is formed on the gate insulating layer 140 to cover the first and second data lines 171 a and 171 b, the data power line 171 c, the first, second, thourd and fourth source electrodes 173 a, 173 b, 173 c and 173 d and the first, second, third and fourth drain electrodes 175 a, 175 b, 175 c and 175 d.
A first contact hole 185 a is formed on the first contact electrode 177 a through the data insulating layer 180. A second contact hole 185 b is formed on the second contact electrode 177 b through the data insulating layer 180. A third contact hole 185 c is formed on the third contact electrode 177 c through the data insulating layer 180. A fourth contact hole 185 d is formed on the fourth contact electrode 177 d through the data insulating layer 180.
A plurality of pixel electrodes 191 is formed on the data metal layer 180. The pixel electrodes 191 includes a first pixel electrode 191 a, a second pixel electrode 191 b, a first common electrode 191 c and a second common electrode 191 d. The pixel electrodes 191 may include a transparent conductive material, a reflective material, etc. Examples of the transparent conductive material that may be used for the pixel electrodes 191 may include indium tin oxide (ITO), indium zinc oxide (IZO), carbon nano tube (CNT), etc. Examples of the reflective material that may be used for the pixel electrodes 191 may include aluminum, silver, chromium, an alloy thereof, etc. These may be used alone or in a combination thereof.
The first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d are formed on the data insulating layer 180. In another embodiment, a transparent metal layer may be patterned to form the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d.
The first pixel electrode 191 a makes contact with the first contact electrode 177 a, and the second pixel electrode 191 b makes contact with the second contact electrode 177 b. The first common electrode 191 c makes contact with the third contact electrode 177 c, and the second common electrode 191 d makes contact with the second contact electrode 177 d.
For example, the pixel electrodes 191 may have a rectangular shape.
The first pixel electrode 191 a and the second common electrode 191 d are electrically connected to the first and fourth drain electrodes 175 a and 175 d, respectively. The first pixel electrode 191 a and the second common electrode 191 d include a first central extension extended in the horizontal direction, and a first branching part extended from the first central extension. An upper portion of the first branching part with respect to the central extension is extended in a first diagonal direction, and a lower portion of the first branching part with respect to the first central extension is extended in a second diagonal direction. The first diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 121. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 121.
The second pixel electrode 191 b and the first common electrode 191 c are electrically connected to the second and third drain electrodes 175 b and 175 c, respectively. The second pixel electrode 191 b and the first common electrode 191 c include a second central extension extended in the horizontal direction, and a second branching part extended from the second central extension. An upper portion of the second branching part with respect to the second central extension is extended in the first diagonal direction, and a lower portion of the first branching part with respect to the central extension is extended in the second diagonal direction. The first diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 121. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 121.
That is, the first and second branching parts in each of the first and second pixels PX(n,n) and PX(n,n+1) alternate with each other to form a comb shape.
The first pixel electrode 191 a is physically and electrically connected to the first drain electrode 175 a through the first contact hole 185 a to receive a voltage from the first drain electrode 175 a. The second pixel electrode 191 b is physically and electrically connected to the second drain electrode 175 b through the second contact hole 185 b to receive a voltage from the second drain electrode 175 b. The first common electrode 191 c is physically and electrically connected to the third drain electrode 175 c through the third contact hole 185 c to receive a voltage from the third drain electrode 175 c. The second common electrode 191 d is physically and electrically connected to the fourth drain electrode 175 d through the fourth contact hole 185 d to receive a voltage from the fourth drain electrode 175 d.
The first and second pixel electrodes 191 a and 191 b, the first and second common electrodes 191 c and 191 d and the liquid crystal layer 300 form a liquid crystal capacitor Clc. In the present embodiment, although the first, second, third and fourth switching elements Qa, Qb, Qc and Qd are turned off, a voltage difference between the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d is maintained. The first drain electrode 175 a electrically connected to the first pixel electrode 191 a and the third drain electrode 175 c electrically connected to the first common electrode 191 c are overlapped with the first storage electrode 133 a, and the gate insulating layer 140 is interposed between the first drain electrode 175 a and the first storage electrode 133 a and between the first common electrode 175 c and the first storage electrode 133 a, thereby forming the first and third storage capacitors Csta and Cstc. The second drain electrode 175 b electrically connected to the second pixel electrode 191 b and the fourth drain electrode 175 d electrically connected to the second common electrode 191 d are overlapped with the second storage electrode 133 b, and the gate insulating layer 140 is interposed between the second drain electrode 175 b and the second storage electrode 133 b and between the second common electrode 175 d and the second storage electrode 133 b, thereby forming the second and fourth storage capacitors Cstb and Cstd. The first, second, third and fourth storage capacitors Csta, Cstb, Cstc and Cstd maintain the voltage difference applied to the liquid crystal capacitor Clc.
The lower alignment layer 11 is formed on the lower base substrate 110 including the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d to align liquid crystal molecules of the liquid crystal layer 300 in a vertical direction. Thus, the liquid crystal molecules of the liquid crystal layer 300 are aligned from the array substrate 100 toward the opposite substrate 200.
The opposite substrate 200 faces the array substrate 100.
The opposite substrate 200 includes an upper base substrate 210, a light blocking pattern 220, a color filter pattern 230, an overcoating layer 250 and an upper alignment layer 21.
The light blocking pattern 220 may prevent leakage of light between adjacent pixel electrodes 191, and defines an opening region facing the pixel electrode 191. The color filter pattern 230 is formed in the opening region defined by the light blocking pattern 220.
The color filter pattern 230 may include a red color filter, a green color filter and a blue color filter. The overcoating layer 230 covers the color filter pattern 230 and the light blocking pattern 220.
The overcoating layer 250 is formed on the light blocking pattern 220 and the color filter pattern 230. The overcoating layer 250 may include an insulating material. For example, the overcoating layer 250 may have a substantially flat surface to cover the color filter 230. Alternatively, the overcoating layer 250 may be omitted.
The upper alignment layer 21 is formed on the overcoating layer 250 to align the liquid crystal molecules of the liquid crystal layer 300 in the vertical direction.
The liquid crystal layer 300 is interposed between the array substrate 100 and the opposite substrate 200. The liquid crystal layer 300 includes the liquid crystal molecules having positive dierectric anisotropy. When the electric field is not applied to the liquid crystal molecules, the liquid crystal molecules are vertically aligned with respect to the surfaces of the array substrate 100 and the opposite substrate 200.
The liquid crystal molecules of the liquid crystal layer 300 vary arrangement in response to the electric field formed between the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d, and thus light transmittance of the liquid crystal layer 300 is changed.
For example, when different voltages are applied to the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d, an electric field substantially parallel with the surfaces of the array substrate 100 and the opposite substrate 200 may be formed between the first and second pixel electrodes 191 a and 191 b and the first and second common electrodes 191 c and 191 d.
Then, the vertically aligned liquid crystal molecules with respect to the array substrate 100 and the opposite substrate 200 change arrangement, so that the liquid crystal molecules are inclined toward the horizontal direction substantially parallel with the direction of the electric field. Thus, polarizing characteristics of the liquid crystal layer 300 are changed, so that the light transmittance of the liquid crystal layer 300 is changed, thereby displaying an image.
When the LCD device uses the vertically aligned liquid crystal molecules, contrast ratio and viewing angle of the LCD device are improved. Also, two different voltages having opposite polarities with respect to the common voltage are applied to the pixel electrode 191, so that driving voltage of the switching elements Qa, Qb, Qc and Qd and the response speed of the liquid crystal molecules are improved. Furthermore, the interference caused by a kickback voltage is prevented, thereby preventing flicker on the LCD device.
FIG. 4 is an equivalent circuit diagram illustrating the LCD device shown in FIG. 1.
Referring to FIGS. 1 to 4, the LCD device includes a plurality of signal lines Dj, Dj+1, −Dj+½, +Dj+1, Gi and Gi+1. The LCD device may further include a plurality of pixels electrically connected to the signal lines Dj, Dj+1, −Dj+½, Gi and Gi+1. The pixels are arranged in a matrix shape.
In FIG. 2, the LCD device includes the array substrate 100, the opposite substrate 200 facing the array substrate 100, and the liquid crystal layer 300 interposed between the array substrate 100 and the opposite substrate 200.
The signal lines Dj, Dj+1, −Dj+½, Gi and Gi+1 includes a first gate line Gi, a second gate line Gi+1, a first data line Dj, a second data line Dj+1, a third data line −Dj+½ and a fourth data line +Dj+½. The first and second gate lines Gi and Gi+1 transmit a gate signal (a scan signal). The first and second data lines Dj and Dj+1 transmit a data voltage. The driving voltage and the ground voltage are applied to the third and fourth data lines −Dj+½ and +Dj+½ by the frame.
The first gate line Gi, the second gate line Gi+1 and the fourth data line +Dj+½ are extended in a column direction, and are substantially parallel with each other. The first data line Dj, the second data line Dj+1 and the third data line −Dj+½ are extended in a row directions and are substantially parallel with each other.
The voltages having the opposite polarities are applied to the first and second data lines Dj and Dj+1, respectively. The voltages having the opposite polarities are applied to the third data line −Dj+½ and the fourth data line +Dj+½.
The driving voltage and the ground voltage are alternately applied to the third and fourth data lines −Dj+½ and +Dj+½ in every frame. For example, an area corresponding to the first and second data lines Dj and Dj+1 is smaller than an area corresponding to the third and fourth data lines −Dj+½ and +Dj+½.
For example, the first and second data lines Dj and Dj+1 of FIG. 4 correspond to the first and second data lines 171 a and 171 b of FIG. 1 formed in the first and second pixels PX(n,n) and PX(n,n+1).
The first gate line Gi of FIG. 4 corresponds to the gate line 121 of FIG. 1.
The third and fourth data lines −Dj+½ and +Dj+½ of FIG. 4 correspond to the data power line 171 c and the gate power line 125 of FIG. 1.
The first second, third and fourth switching elements Qa, Qb, Qc and Qd are electrically connected to the first and second data lines 171 a and 171 b, the data power line 171 c and the gate power line 125.
Referring again to FIG. 4, the first, second, third and fourth data lines Dj, Dj+1, −Dj+½ and +Dj+½ are electrically connected to the first, second, third and fourth switching elements Qa, Qb, Qc and Qd.
Alternatively, the first and second data lines Dj and Dj+1 may be electrically connected to a fifth switching element Qe and a sixth switching element Qf, respectively. Also, the third and fourth data lines −Dj+½ and +Dj+½ may be electrically connected to a seventh switching element Qg and a eighth switching element Qh. The fifth, sixth, seventh and eighth switching elements Qe, Qf, Qg and Qh may be electrically connected to the second gate line Gi+1.
A third pixel PX(n+1,n) and a fourth pixel PX(n+1,n+1) may be disposed on a next line to the first and second pixels PX(n,n) and PX(n,n+1). The fifth and eighth switching elements Qe and Qh may be formed in the third pixel PX(n+1,n). The sixth and seventh switching elements Qf and Qg may be formed in the fourth pixel PX(n+1,n+1).
Referring again to FIGS. 1 and 4, the branching part of the first pixel electrode 1191 a and the brahcning part of the first common electrode 191 c are alternately arranged. The branching part of the second pixel electrode 191 b and the branching part of the second common electrode 191 d are alternately arranged.
For example, a branching part of the third pixel electrode electrically connected to the fifth switching element Qe and a branching part of the fourth common electrode electrically connected to the eighth switching element Qh are alternately arranged. Also, a branching part of the fourth pixel electrode electrically connected to the sixth switching element Qf and a branching part of the third common electrode electrically connected to the seventh switching element Qg are alternately arranged.
Voltages having opposite polarities are applied to the first data line Dj and the second data line Dj+1. Voltages having opposite polarities are applied to the third data line −Dj+½ and the fourth data line +Dj+½. Thus, adjacent pixels of the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,n) and PX(n+1,n+1) receive different voltages having the opposite polarities.
Referring again to FIGS. 1 to 4, the storage line 131 is overlapped with the pixel electrodes electrically connected to the first, second, third, fourth, fifth, sixth, seventh and eighth switching elements Qa, Qb, Qc, Qd, Qe, Qf, Qg and Qh to form first, second, third, fourth, fifth, sixth, seventh and eighth storage capacitors Cst1, Cst2, Cst3, Cst4, Cst5, Cst6, Cst7 and Cst8, respectively. For example, the ground voltage may be applied to the storage line 131.
The liquid crystal layer 300 in the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,n) and PX(n+1,n+1) functions as a dielectric material of the liquid crystal capacitor Clc. The liquid crystal capacitor Clc is formed by the pixel electrodes and the liquid crystal layer 300.
The liquid crystal layer 300 has dielectric anisotropy. When the electric field is not applied to the liquid crystal layer 300, the liquid crystal molecules of the liquid crystal layer 300 are vertically aligned between the array substrate 100 and the opposite substrate 200.
Hereinafter, a method of manufacturing the array sustrate will be explained with reference to FIGS. 1 to 4.
The gate line 121, the gate power line 125 and the storage line 131 are substantially parallel with each other.
The first and third gate electrodes 124 a and 124 c correspond to the first pixel PX(n,n). The second and fourth gate electrodes 124 b and 124 d correspond to the second pixel PX(n,n+1). The first storage electrode 133 a corresponds to the first pixel PX(n,n). The second storage electrode 133 b corresponds to the second pixel PX(n,n+1). The gate power electrode 127 corresponds to the second pixel PX(n,n+1).
The gate insulating layer 140 is formed on the lower base substrate 110 having the first, second, third and fourth gate electrodes 124 a, 124 b, 124 c and 124 d, the first and second storage electrodes 133 a and 133 b and the gate power electrode 127. The data metal layer including the first data line 171 a, the second data line 171 b, the data power line 171 c, the first drain electrode 175 a, the second drain electrode 175 b, the third drain electrode 175 c, the fourth drain electrode 175 d, the first source electrode 173 a, the second source electrode 173 b, the third source electrode 173 c and the fourth source electrode 173 d is formed.
The first data line 171 a, the second data line 171 b and the data power line 171 c are substantially parallel with each other.
The first switching element Qa electrically connected to the first data line 171 a and the gate line 121, the second switching element Qb electrically connected to the second data line 171 b and the gate line 121, the third switching element Qc electrically connected to the data power line 171 c and the gate line 121 and the fourth switching element Qd electrically connected to the gate power line 125 and the gate line 121 are formed on the gate insulating layer 140. The gate power line 125 receives a voltage having different polarity from the data power line 171 c.
The fifth and eighth switching elements Qe and Qh are formed in the thid pixel PX(n+1,n). The sixth and seventh switching elements Qf and Qg are formed in the fourth pixel PX(n+1,n+1).
The data metal layer 180 is then formed.
The first pixel electrode 171 a electrically connected to the first switching element Qa, the second pixel electrode 191 b electrically connected to the second switching element Qb, the first common electrode 191 c electrically connected to the third switching element Qc and the second common electrode 191 d electrically connected to the fourth switching element Qd are formed on the gate insulating layer 140 having the data metal layer 180.
The first pixel electrode 191 a and the first common electrode 191 c are formed in the first pixel PX(n,n). The second pixel electrode 191 b and the second common electrode 191 d are formed in the second pixel PX(n,n+1). The second pixel PX(n,n+1) is adjacent to the frst pixel PX(n,n) along the first data line 171 a.
The thid pixel electrode electrically connected to the fifth switching element Qe, the fourth pixel electrode electrically connected to the switching element Qf, the third common electrode electrically connected to the seventh switching element Qg and the fourth common electrode electrically connected to the eighth switching element Qh are then formed.
The lower alignment layer 11 is formed on the lower base substrate 110 having the first, second, third and fourth pixel electrodes 191 a and 191 b, the first, second, third and fourth common electrodes 191 c and 191 d.
Different voltages having opposite polarities are alternately applied to the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,1) and PX(n+1,n+1), so that a dot inversion is performed in the LCD device in every frame.
Alternatively, when a voltage having substantially the same polarity is pplied to the third and fourth data lines −Dj+½ and +Dj+½, the first and third pixels PX(n,n) and PX(n+1,n) that are adjacent to each other in the horizontal direction may receive the voltage having the same level and the second and fourth pixels PX(n,n+1) and PX(n+1,n+1) that are adjacent to each other in the horizontal direction may receive the voltage having the same level that is different from the lefel of the voltage applied to the first and third pixels PX(n,n) and PX(n+1,n). Thus, the first and third pixels PX(n,n) and PX(n+1,n) receive different voltage from the second and fourth pixels PX(n,N+1) and PX(n+1,n+1), so that a line inversion may be performed in every frame.
The levels of the voltages applied to the data lines of the signal lines Dj, Dj+1, −Dj+½, +Dj+½, Gi and Gi+1 are changed so that the dot inversion or the line inversion may be performed.
According to the present embodiment, the data power line 171 c and the gate power line 125 receive the voltages having the opposite polarities, so that the voltages having the different polarities may be applied to each of the pixels and opening ratio of the pixels is increased.
FIG. 5 is a plan view illustrating an LCD device in accordance with another embodiment of the present invention. FIG. 6 is a cross-sectinoal view taken along a line III-III′ shown in FIG. 5. FIG. 7 is a cross-sectional view taken along a line IV-IV′ shown in FIG. 5. The LCD device of FIGS. 5 to 7 is same as in FIGS. 1 to 4 except an array substrate 400. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 1 to 4 and any further explanation concerning the above elements will be omitted.
Referring to FIGS. 5 to 7, the LCD device includes an array substrate 400, an opposite substrate 200 and a liquid crystal layer 300.
In FIG. 5, a first pixel PX(n,n) and a second pixel PX(n,n+1) of the LCD device are illustrated.
The array substrate 400 includes a lower base substrate 410. A pixel region is defined in the lower base substrate 410.
The lower base substrate 410 has a plate shape. A transparent material that may be used for the lower base substrate 410 may include glass, quartz, synthetic resin, etc. These may be used alone or in a combination thereof.
A gate metal layer is formed on the lower base substrate 410. The gate metal layer may include agate line 421, a first power line 431 and a second power line 435.
The gate line 421 is extended in a longitudinal direction to transmit a gate signal. Each of the gate lines 421 includes a first gate electrode 424 a, a second gate electrode 424 b, a third gate electrode 424 c and a fourth gate electrode 424 d that are upwardly protruded. The first and third gate electrodes 424 a and 424 c correspond to the first pixel PX(n,n). The second and fourth gate electrodes 424 b and 424 d correspond to the second pixel PX(n,n+1).
The first power line 431 receives a ground voltage, and is extended in the longitudinal direction. Each of the first power line 431 is interposed between two adjacent gate lines 421, and is adjacent to a lower one of the two adjacent gate lines 421. Each of the first power line 431 includes a first power electrode 433. The first power electrode 433 corresponds to the first pixel PX(n,n).
The second power line 435 receives a predetermined voltage, and is extended in the longitudinal direction. Each of the second power line 435 is interposed between the first power line 435 and the lower one of the two adjacent gate lines 421. Each of the second power line 435 includes a second power electrode 437. The second power electrode 437 corresponds to the second pixel PX(n,n+1).
The gate insulating layer 440 is formed on the lower base substrate 410 to cover the gate line 421, the first, second, third and fourth gate electrodes 424 a, 424 b, 424 c and 424 d, and the first and second power electrodes 433 and 437.
A first gate contact hole 434 a is formed on the first power electrode 433 through the gate insulating laeyr 440. A second gate contact hole 434 b is formed on the second power electrode 437 through the gate insulating layer 440.
A first semiconductor layer 454 a, a second semicnodcutor layer 454 b, a third semiconductor layer 454 c and a fourth semiconductor layer 454 d are formed on the gate insulating layer 440. The first, second, third and fourth semiconductor layers 454 a, 454 b, 454 c and 454 d are formed on the first, second, third and fourth gate electrodes 424 a, 424 b, 424 c and 424 d, respectively.
Two first ohmic contact layers 463 a and 465 a are formed on the first semiconductor layers 454 a. Two second ohmic contact layers 463 b and 465 b are formed on the second semiconductor layers 454 b. Two third ohmic contact layers 463 c and 465 c are formed on the third semiconductor layers 454 c. Two fourth ohmic contact layers 463 d and 465 d are formed on the fourth semiconductor layers 454 d. The first, second, third and fourth ohmic contact layers 463 a, 463 b, 463 c, 463 d, 465 a, 465 b, 465 c and 465 d may include n+ hydrogenated amorphous silicon that is implanted by n type impurities at a high concentration, silicide, etc.
A data metal layer including a first data line 471 a, a second data line 471 b, a third data line 471 c, a first drain electrode 475 a, a second drain electrode 475 b, a third drain electrode 475 c and a fourth drain electrode 475 d is formed on the first, second, third and fourth ohmic contact layers 463 a, 463 b, 463 c, 463 d, 465 a, 465 b, 465 c and 465 d and the gate insulating layer 440.
The first, second and third data lines 471 a, 471 b and 471 c transmit data signals. The first, second and third data lines 471 a, 471 b and 471 c are extended in a horizontal direction crossing the gate line 421 and the first and second power lines 431 and 435.
The first data line 471 a includes a first source electrode 473 a having U-shape bent toward the first gate electrode 424 a. The second data line 471 b includes a second source electrode 473 b having U-shape bent toward the second gate electrode 424 b. The first power line 431 includes a third source electrode 473 c having U-shape bent toward the third gate electrode 424 c. The second power line 435 includes a fourth source electrode 473 d having U-shape bent toward the fourth gaate electrode 424 d.
An end of a rod shape of each of the first, second, third and fourth drain electrodes 475 a, 475 b, 475 c and 475 d faces each of the first, second, third and fourth source electrodes 473 a, 473 b, 473 c and 473 d, and is surrounded by each of the first, second, third and fourth source electrodes 473 a, 473 b, 473 c and 473 d, respectively.
The first source electrode 473 a is directly connected to the first data line 471 a. The second source electrode 473 b is directly connected to the second data line 471 b. The third source electrode 473 c is connected to the first power line 431 through the first gate contact hole 434 a. The fourth source electrode 473 d is connected to the second power line through the second gate contact hole 434 b.
The first gate electrode 424 a, the first source electrode 473 a, the first drain electrode 475 a and the first semiconductor layer 454 a form a first switching element Qa. The second gate electrode 424 b, the second source electrode 473 b, the second drain electrode 475 b and the second semiconductor layer 454 b form a second switching element Qb. The third gate electrode 424 c, the third source electrode 473 c, the third drain electrode 475 c and the third semiconductor layer 454 c form a third switching element Qc. The fourth gate electrode 424 d, the fourth source electrode 473 d, the fourth drain electrode 475 d and the fourth semiconductor layer 454 d form a fourth switching element Qd.
A channel of the first switching element Qa is formd in the first semiconductor layer 454 a between the first source electrode 473 a and the first drain electrode 475 a. A channel of the second switching element Qb is formd in the second semiconductor layer 154 b between the second source electrode 473 b and the second drain electrode 475 b. A channel of the third switching element Qc is formd in the third semiconductor layer 454 c between the third source electrode 473 c and the third drain electrode 475 c. A channel of the fourth switching element Qd is formd in the fourth semiconductor layer 454 d between the fourth source electrode 473 d and the fourth drain electrode 475 d.
A first one 463 a of the two first ohmic contact layers 463 a and 465 a is interposed between the first semiconductor layer 454 a and the first source electrode 473 a to decrease contact resistance between the first semiconductor layer 454 a and the first source electrode 473 a, and a second one 465 a of the two first ohmic contact layers 463 a and 465 a is interposed to between the first semiconductor layer 454 a and the first drain electrode 475 a to decrease contact resistance between the first semiconductor layer 454 a and the first drain electrode 475 a. A first one 463 b of the two second ohmic contact layers 463 b and 465 b is interposed between the second semiconductor layer 454 b and the second source electrode 473 b to decrease contact resistance between the second semiconductor layer 454 b and the second source electrode 473 b, and a second one 465 b of the two second ohmic contact layers 463 b and 465 b is interposed between the second semiconductor layer 454 b and the second drain electrode 475 b to decrease contact resistance between the second semiconductor layer 454 b and the second drain electrode 475 b. A first one 463 c of the two third ohmic contact layers 463 c and 465 c is interposed between the third semiconductor layer 454 c and the third source electrode 473 c to decrease contact resistance between the third semiconductor layer 454 c and the third source electrode 473 c, and a second one 465 c of the two third ohmic contact layers 463 c and 465 c is interposed between the third semiconductor layer 454 c and the third drain electrode 475 c to decrease contact resistance between the third semiconductor layer 454 c and the third drain electrode 475 c. A first one 463 d of the two fourth ohmic contact layers 463 d and 465 d is interposed between the fourth semiconductor layer 454 d and the fourth source electrode 473 d to decrease contact resistance between the fourth semiconductor layer 454 d and the fourth source electrode 473 d, and a second one 465 d of the two fourth ohmic contact layers 463 d and 465 d is interposed between the fourth semiconductor layer 454 d and the fourth drain electrode 475 d to decrease contact resistance between the fourth semiconductor layer 454 d and the fourth drain electrode 475 d.
The first switching element Qa is electrically conneted to the first data line 471 a. The third switching element Qc is electrically conneted to the first power line 431. The first and third switching elements Qa and Qc are formed in the first pixel PX(n,n).
The second switching element Qb is electrically conneted to the second data line 471 b. The fourth switching element Qd is electrically conneted to the second power line 435. The second and fourth switching elements Qb and Qd are formed in the second pixel PX(n,n+1).
Voltages having opposite levels are applied to the first and second data lines 471 a and 471 b, respectively.
The data insulating layer 480 is formed on the gate insulating layer 440 to cover the first and second data lines 471 a and 471 b, the first, second, third and fourth source electrodes 473 a, 473 b, 473 c and 473 d, and the first, second, third and fourth drain electrodes 475 a, 475 b, 475 c and 475 d.
A first contact hole 434 a is formed on the first contact electrode 477 a connected to the first drain electrode 475 a through the data insulating layer 480. A second contact hole 434 b is formed on the second contact electrode 477 b connected to the second drain electrode 475 b through the data insulating layer 480. A third contact hole 434 c is formed on the third contact electrode 477 c connected to the third drain electrode 475 c through the data insulating layer 480. A fourth contact hole 434 d is formed on the fourth contact electrode 477 d connected to the fourth drain electrode 475 d through the data insulating layer 480.
A plurality of pixel electrodes 491 is formed on the data metal layer 480. The pixel electrodes 491 includes a first pixel electrode 491 a, a second pixel electrode 491 b, a first common electrode 491 c and a second common electrode 491 d. The pixel electrodes 491 may include a transparent conductive material, a reflective material, etc. Examples of the transparent conductive material that may be used for the pixel electrodes 491 may include indium tin oxide (ITO), indium zinc oxide (IZO), carbon nano tube (CNT), etc. Examples of the reflective material that may be used for the pixel electrodes 491 may include aluminum, silver, chromium, an alloy thereof, etc. These may be used alone or in a combination thereof.
The first and second pixel electrodes 491 a and 491 b and the first and second common electrodes 491 c and 491 d are formed on the data insulating layer 480. In another embodiment, a transparent metal layer may be patterned to form the first and second pixel electrodes 491 a and 491 b and the first and second common electrodes 491 c and 491 d.
The first pixel electrode 491 a makes contact with the first contact electrode 477 a, and the second pixel electrode 491 b makes contact with the second contact electrode 477 b. The first common electrode 491 c makes contact with the third contact electrode 477 c, and the second common electrode 491 d makes contact with the second contact electrode 477 d.
For example, the pixel electrodes 491 may have a rectangular shape.
The first and second pixel electrodes 491 a and 491 b include a first central extension, a first main branching part and a first branching part. The first central extension is electrically connected to the first and second drain electrodes 475 a and 475 b to be extended in the horizontal direction. The first main branching part crosses a center of the first central extension in the longitudinal direction. An upper portion of the first branching part with respect to the central extension is extended in a first diagonal direction, and a lower portion of the first branching part with respect to the first central extension is extended in a second diagonal direction. The first diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 421. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 421.
A distance beween the center of the first central extension and the first branching parts is greater than a distance between an end of the first central extension and the first branching parts.
The first and second common electrodes 491 c and 491 d include a second central extension, a second main branching part and a second branching part. The second central extension is electrically connected to the third and fourth drain electrodes 475 c and 475 d to be extended in the horizontal direction. The second main branching part crosses a center of the second central extension in the longitudinal direction. An upper portion of the second branching part with respect to the central extension is extended in the first diagonal direction, and a lower portion of the second branching part with respect to the second central extension is extended in the second diagonal direction. The second diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 421. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 421.
A distance beween the center of the second central extension and the second branching parts is greater than a distance between an end of the second central extension and the second branching parts.
That is, the first and second branching parts in each of the first and second pixels PX(n,n) and PX(n,n+1) alternate with each other to form a comb shape.
The first pixel electrode 491 a is physically and electrically connected to the first drain electrode 475 a through the first contact hole 434 a to receive a voltage from the first drain electrode 475 a. The second pixel electrode 491 b is physically and electrically connected to the second drain electrode 475 b through the second contact hole 434 b to receive a voltage from the second drain electrode 475 b. The first common electrode 491 c is physically and electrically connected to the third drain electrode 475 c through the third contact hole 434 c to receive a voltage from the third drain electrode 475 c. The second common electrode 491 d is physically and electrically connected to the fourth drain electrode 475 d through the fourth contact hole 434 d to receive a voltage from the fourth drain electrode 475 d. The first and second pixel electrodes 491 a and 491 b, the first and second common electrodes 491 c and 491 d and the liquid crystal layer 300 form a liquid crystal capacitor Clc. In the present embodiment, although the first, second, third and fourth switching elements Qa, Qb, Qc and Qd are turned off, a voltage difference between the first and second pixel electrodes 491 a and 491 b and the first and second common electrodes 491 c and 491 d is maintained.
The first pixel electrode 491 a and the first common electrode 491 c are partially overlapped with the first power electrodes 433, and the data insulating layer 480 is interposed between the first pixel electrode 491 a and the first power lines 433 and between the first common electrode 491 c and the first power lines 433, thereby forming first storage capacitors Csg. The second pixel electrode 491 b and the second common electrode 491 d are partially overlapped with the second power electrodes 437, and the data insulating layer 480 is interposed between the second pixel electrode 491 b and the second power lines 437 and between the second common electrode 491 d and the second power lines 437, thereby forming second storage capacitors Csa, thereby forming the second storage capacitors Csa. The first and second storage capacitors Csg and Csa maintain the voltage difference applied to the liquid crystal capacitor Clc.
For example, the first storage capacitors Csg formed by overlapping the first pixel electrode 491 a and the first power electrodes 433 and overlapping the first common electrode 491 c and the first power electrodes 433 have substantially the same capacity as the second storage capacitors Csa formed by overlapping the second electrode 491 a and the second power electrodes 437 and overlapping the second common electrode 491 d and the second power electrodes 437.
The lower alignment layer 41 is formed on the lower base substrate 410 including the first and second pixel electrodes 491 a and 491 b and the first and second common electrodes 491 c and 491 d to align liquid crystal molecules of the liquid crystal layer 300 in a vertical direction. Thus, the liquid crystal molecules of the liquid crystal layer 300 are aligned from the array substrate 100 toward the opposite substrate 200.
FIG. 8 is an equivalent circuit diagram illustrating the LCD device shown in FIG. 5.
Referring to FIGS. 5 to 8, the LCD device includes a plurality of signal lines Dj, Dj+1, Dj+2, Gi and Gi+1, a ground line GND and a power supply line ADD. The LCD device may further include a plurality of pixels electrically connected to the signal lines Dj, Dj+1, Dj+2, Gi and Gi+1, the ground line GND and the power supply line ADD. The pixels are arranged in a matrix shape.
In FIG. 6, the LCD device includes the array substrate 400, the opposite substrate 200 facing the array substrate 100, and the liquid crystal layer 300 interposed between the array substrate 400 and the opposite substrate 200.
The signal lines Dj, Dj+1, Dj+2, Gi and Gi+1 includes a first gate line Gi, a second gate line Gi+1, a first data line Dj, a second data line Dj+1 and a third data line Dj+2. The first and second gate lines Gi and Gi+1 transmit a gate signal (a scan signal). The first second and third data lines Dj, Dj+1 and Dj+2 transmit a data voltage.
The first gate line Gi, the second gate line Gi+1, the ground line GND and the power supply line ADD are extended in a column direction, and are substantially parallel with each other. The first data line Dj, the second data line Dj+1 and the third data line Dj+2 are extended in a row direction, and are substantially parallel with each other.
The voltages having the opposite polarities are applied to the first and second data lines Dj and Dj+1, respectively. The voltage applied to the third data line Dj+2 has substantially the same polarity as the first data line Dj.
For example, the first, second and third data lines Dj, Dj+1 and Dj+2, of FIG. 8 correspond to the first, second and third data lines 471 a, 471 b and 471 c of FIG. 5 formed in the first and second pixels PX(n,n) and PX(n,n+1).
The first gate line Gi of FIG. 8 corresponds to the gate line 421 of FIG. 5.
The ground line GND and the power supply line ADD of FIG. 8 correspond to the first power line 431 and the second power line 435 of FIG. 5, respectively.
The first and second switching transistors Qa and Qb are electrically connected to the first and second data lines 471 a and 471 b, respectively. The third and fourth switching transistors Qc and Qd are electrically connected to the first and second power lines 431 and 435, respectively.
Referring again to FIG. 8, the first and second data lines Dj and Dj+1 are electrically connected to the first and second switching elements Qa and Qb, respectively. The ground line GND and the power supply line ADD are electrically connected to the first and second switching elements Qe and Qd, respectively.
Alternatively, the second and third data lines Dj+1 and Dj+2 may be electrically connected to a fifth switching element Qe and a sixth switching element Qf, respectively. Also, the power supply line ADD and the ground line GNU may be electrically connected to a seventh switching element Qg and an eighth switching element Qh.
A third pixel PX(n+1,n) and a fourth pixel PX(n+1,n+1) may be disposed on a next line to the first and second pixels PX(n,n) and PX(n,n+1).
The fifth and seventh switching elements Qe and Qg may be formed in the third pixel PX(n+1,n). The sixth and eighth switching elements Qf and Qh may be formed in the fourth pixel PX(n+1,n+1).
The filth, sixth, seventh and eighth switching elements Qe, Qf, Qg and Qh are operated using the second gate line Gi+1.
The voltages having the opposite polarities are applied to the first data line Dj and the second data line Dj+1. The ground voltage is applied to the ground line GND, and a predetermined power voltage is applied to the power supply line ADD.
Thus, adjacent pixels of the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,n) and PX(n+1,n+1) receive different voltages having the opposite polarities.
Referring again to FIGS. 5 and 8, the ground line GND and the power supply line ADD are overlapped with the pixel electrodes electrically connected to the first, second, third, fourth, fifth, sixth, seventh and eighth switching elements Qa, Qb, Qc, Qd, Qe, Qf, Qg and Qh to form first and second storage capacitors Csg and Csa.
The liquid crystal layer 300 in the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,n) and PX(n+1,n+1) functions as a dielectric material of the liquid crystal capacitor Clc. The liquid crystal capacitor Clc is formed by the pixel electrodes and the liquid crystal layer 300.
The liquid crystal layer 300 has dielectric anisotropy. When the electric field is not applied to the liquid crystal layer 300, the liquid crystal molecules of the liquid crystal layer 300 are vertically aligned between the array substrate 400 and the opposite substrate 200.
Hereinafter, a method of manufacturing the array sustrate will be explained with reference to FIGS. 5 to 8.
The gate line 421, the first power line 431 and the second power line 435 are substantially parallel with each other.
The first and third gate electrodes 424 a and 424 c correspond to the first pixel PX(n,n). The second and fourth gate electrodes 424 b and 424 d correspond to the second pixel PX(n,n+1). The first storage electrode 433 corresponds to the first pixel PX(n,n). The second storage electrode 437 corresponds to the second pixel PX(n,n+1).
The gate insulating layer 140 is then formed on the lower base substrate 410.
A data metal layer including the first, second and third data lines 471 a, 471 b and 471 c, the first, second, third and fourth drain electrodes 475 a, 475 b, 475 c and 475 d and the first, second, third and fourth source electrodes 473 a, 473 b, 473 c and 473 d is formed.
The first data line 471 a, the second data line 471 b and the third data line 471 c are substantially parallel with each other.
The data insulating layer 480 is then formed.
The first and second pixel electrodes 491 a and 491 b and the first and second common electrodes 491 c and 491 d are then formed on the lower base substrate 410 having the data insulating layer 480. The first pixel electrode 491 a and the first common electrode 491 c are partially overlapped with the first power electrode 433, and the date insulating layer 480 is interposed between the first pixel electrode 491 a and the first power electrode 433 and between the first common electrode 491 c and the first power electrode 433, thereby forming the first storage capacitors Csg. The second pixel electrode 491 b and the second common electrode 491 d are partially overlapped with the second power electrode 437, and the date insulating layer 480 is interposed between the second pixel electrode 491 b and the second power electrode 437 and between the second common electrode 491 d and the second power electrode 437, thereby forming the second storage capacitors Csa.
The lower alignment layer 11 is then formed.
Different voltages having opposite polarities are alternately applied to the first, second, third and fourth pixels PX(n,n), PX(n,n+1), PX(n+1,1) and PX(n+1,n+1), so that a dot inversion is performed in the LCD device in every frame.
Alternatively, when the ground line GND or the power supply line ADD is electrically connected in line-by-line connection, a voltage having substantially the same polarity is pplied to the pixels aligned along the first gate line Gi, so that a line inversion may be performed in every frame. For example, the line inversion may be a horizontal line inversion.
The levels of the voltages applied to the data lines of the signal lines Dj, Dj+1, Dj/2, Gi and Gi+1 are changed so that the dot inversion or the line inversion may be performed.
According to the present embodiment, the first power line 431 and the second power line 435 are overlapped with the pixel electrodes to form the storage capacitors, so that opening ratio of the pixels is increased.
FIG. 9 is a plan view illustrating an LCD device in accordance with still another embodiment of the present invention.
The LCD device of FIG. 9 is same as in FIGS. 5 to 7 except an array substrate 500. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 5 to 7 and any further explanation concerning the above elements will be omitted.
Referring to FIGS. 6 to 9, the LCD device includes an array substrate 500, an opposite substrate 200 and a liquid crystal layer 300.
The array substrate 500 of FIG. 9 is same as in FIG. 5 except a pixel electrode 591 a and a common electrode 591 b. Thus, the same reference numerals will be used for refer to the same or line parts as those described in FIG. 5 and any further explanation concerning the above elements will be omitted. In FIG. 9, a first pixel PX(n,n) and a second pixel PX(n,n+1) of the LCD device are illustrated.
The array substrate 500 includes a lower base substrate 410. A pixel region is defined in the lower base substrate 410.
The lower base substrate 410 has a plate shape. A transparent material that may be used for the lower base substrate 410 may include glass, quartz, synthetic resin, etc. These may be used alone or in a combination thereof.
A data insulating layer 480 is formed on the lower base substrate 410. A plurality of pixel electrodes 591 is formed on the data insulating layer 480. The pixel electrodes 591 includes a first pixel electrode 591 a, a second pixel electrode 591 b, a first common electrode 591 c and a second common electrode 591 d. The pixel electrodes 591 may include a transparent conductive material, a reflective material, etc. Examples of the transparent conductive material that may be used for the pixel electrodes 591 may include indium tin oxide (ITO), indium zinc oxide (IZO), carbon nano tube (CNT), etc. Examples of the reflective material that may be used for the pixel electrodes 591 may include aluminum, silver, chromium, an alloy thereof, etc. These may be used alone or in a combination thereof.
The first and second pixel electrodes 591 a and 591 b and the first and second common electrodes 591 c and 591 d are formed on the data insulating layer 480. In another embodiment, a transparent metal layer may be patterned to form the first and second pixel electrodes 591 a and 591 b and the first and second common electrodes 591 c and 591 d.
The pixel electrodes 591 may have a quadrangular shape.
The first pixel electrode 591 a is electrically connected to the first drain electrode 475 a, and the second pixel electrode 591 b is electrically connected to the second drain electrode 475 b. The first and second pixel electrodes 591 a and 591 b include a plurality of first bending branches that are extended in the horizontal direction and are leftwardly and rightwardly bent to have shapes of inequality sign.
A lower portion and an upper portion of each of the first and second pixel electrodes 591 a and 591 b are extended in a first diagonal direction, and a central portion of each of the first and second pixel electrodes 591 a and 591 b is extended in a second diagonal direction. The first bending branches surrounds the first and second pixels PX(n,n) and PX(n,n+1). A lower portion and an upper portion of each of the first bending branches are extended in the first diagonal direction, and a central portion of each of the first bending branches is extended in the second diagonal direction.
The first diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 421. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 421.
The first common electrode 591 c is electrically connected to the third drain electrode 475 c, and the second common electrode 591 d is electrically connected to the second drain electrode 475 d. The first and second common electrodes 591 c and 591 d include a plurality of second bending branches that are extended in the horizontal direction and are leftwardly and rightwardly bent to have shapes of inequality sign.
A lower portion and an upper portion of each of the first and second common electrodes 591 c and 591 d are extended in the first diagonal direction, and a central portion of each of the first and second common electrodes 591 c and 591 d is extended in the second diagonal direction. A lower portion and an upper portion of each of the second bending branches are extended in the first diagonal direction, and a central portion of each of the second bending branches is extended in the second diagonal direction.
The first diagonal direction may form an angle of about 45 degrees or about 225 degrees with respect to the gate line 421. The second diagonal direction may form an angle of 135 degrees or about 315 degrees with respect to the gate line 421.
The central portion of the second bending branches of the first and second common electrodes 591 c and 591 d is overlapped with the second and third data lines 571 b and 571 c in a first area A1.
The lower and upper portions of the second bending branches of the first and second common electrodes 591 c and 591 d are overlapped with the first and second data lines 571 a and 571 b in a first area A2.
For example, the second bending branches may be overlapped with about a half of the first and second data lines 571 a and 571 b in the first pixel PX(n,n), and about a half of the second and third data lines 571 b and 571 c in the second pixel P(n,n+1).
Voltages having opposite polarities are applied to adjacent data lines, so that parasite capacitance caused by the data lines may be prevented. Thus, the voltages applied to the data lines have constant level.
That is, the first and second bending branches in each of the first and second pixels PX(n,n) and PX(n,n+1) alternate with each other to form a comb shape.
A distance between the first and second bending branches in a peripheral region of the first and second pixels PX(n,n) and PX(n,n+1) is greater than a distance between the first and second bending branches in a central region of the first and second pixels PX(n,n) and PX(n,n+1).
The first pixel electrode 591 a is physically and electrically connected to the first drain electrode 475 a through the first contact hole 434 a to receive a voltage from the first drain electrode 475 a. The second pixel electrode 591 b is physically and electrically connected to the second drain electrode 475 b through the second contact hole 434 b to receive a voltage from the second drain electrode 475 b. The first common electrode 591 c is physically and electrically connected to the third drain electrode 475 c through the third contact hole 434 c to receive a voltage from the third drain electrode 475 c. The second common electrode 591 d is physically and electrically connected to the fourth drain electrode 475 d through the fourth contact hole 434 d to receive a voltage from the fourth drain electrode 475 d. The first and second pixel electrodes 591 a and 591 b, the first and second common electrodes 591 c and 591 d and the liquid crystal layer 300 form a liquid crystal capacitor Clc. In the present embodiment, although the first, second, third and fourth switching elements Qa, Qb, Qe and Qd are turned off, a voltage difference between the first and second pixel electrodes 591 a and 591 b and the first and second common electrodes 591 c and 591 d is maintained.
An equivalent circuit diagram of the LCD device shown in FIG. 9 is the same as to the equivalent circuit diagram of FIG. 8. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIG. 8 and any further explanation concerning the above elements will be omitted.
The method of manufacturing the LCD device of FIG. 9 is the same as the method of manufacturing the LCD device of FIGS. 1 to 4. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 1 to 4 and any further explanation concerning the above elements will be omitted.
According to the present embodiment, the adjacent data lines receive the voltages having the different polarities, so that the parasite capacitance between the adjacent data lines may be removed. Thus, the voltage having the constant level may be applied to the data lines.
FIG. 10 is a plan view illustrating an LCD device in accordance with further still another embodiment of the present invention.
The LCD device of FIG. 10 is same as in FIGS. 1 to 4 except an array substrate 600. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 1 to 4 and any further explanation concerning the above elements will be omitted.
Referring to FIGS. 6 and 10, the LCD device includes an array substrate 600, an opposite substrate 200 and a liquid crystal layer 300.
The array substrate 600 includes a lower base substrate 610. A pixel region is defined in the lower base substrate 610.
The lower base substrate 610 has a plate shape. A transparent material that may be used for the lower base substrate 610 may include glass, quartz, synthetic resin, etc.
A gate metal layer is formed on the lower base substrate 610. The gate metal layer may include a gate line 621 and a storage line 631.
The gate line 621 is extended in a longitudinal direction to transmit a gate signal. Each of the gate lines 621 includes a first gate electrode 624 a and a second gate electrode 624 b.
The storage line 631 receives a voltage such as a common voltage, and is extended in the longitudinal direction. Each of the storage lines 631 is interposed between two adjacent gate lines 621, and is adjacent to a lower gate line 621 of the two adjacent gate lines 621. The storage line 631 includes a storage electrode 633. The storage electrode 633 has substantially rectangular shape, and two lower corners of the storage electrode 633 are chamfered. Alternatively, the storage electrode 633 may have various shapes and arrangements.
The gate insulating layer 640 is formed on the lower base substrate 610 to cover the gate line 621, the first and second gate electrodes 624 a and 124 b, the storage line 631 and the storage electrode 633.
A first semiconductor layer 654 a and a second semicnodcutor layer 654 b are formed on the gate insulating layer 640. The first and second semiconductor layers 654 a and 654 b may include hydrogenated amorphous silicon, polycrystalline silicon, etc. The first and second semiconductor layers 654 a and 654 b are formed on the first and second gate electrodes 624 a and 624 b, respectively.
Two first ohmic contact layers 663 a and 665 a are formed on the first semiconductor layers 654 a. Two second ohmic contact layers 663 b and 665 b are formed on the second semiconductor layers 654 b. The first and second ohmic contact layers 663 a and 665 a may include n+ hydrogenated amorphous silicon that is implanted by n type impurities at a high concentration, silicide, etc.
A data metal layer including a first data line 671 a, a second data line 671 b, a first drain electrode 675 a and a second drain electrode 675 b is formed on the ohmic contact layers 663 a and 665 a and the gate insulating layer 640.
The first and second data lines 671 a and 671 b transmit data signals, and are extended in the horizontal direction crossing the gate line 621 and the storage line 631.
The first data line 671 a includes a first source electrode 673 a bent toward the first gate electrode 624 a. The second data line 671 b includes a second source electrode 673 b bent toward the second gate electrode 624 b.
An end of a rod shape of each of the first and second drain electrodes 675 a and 675 b faces each of the first and second source electrodes 673 a and 673 b, and is surrounded by each of the first and second source electrodes 673 a and 673 b.
A first contact electrode 677 a connected to the first drain electrode 675 a is overlapped with a left half of the storage electrode 633, and a second contact electrode 677 b connected to the second drain electrode 675 b is overlapped with a right half of the storage electrode 633.
The first gate electrode 624 a, the first source electrode 673 a, the first drain electrode 675 a and the first semiconductor layer 654 a form a first switching element Qa. The second gate electrode 624 b, the second source electrode 673 b, the second drain electrode 675 b and the second semiconductor layer 654 b form a second switching element Qb.
A channel of the first switching element Qa is formd in the first semiconductor layer 654 a between the first source electrode 673 a and the first drain electrode 675 a. A channel of the second switching element Qb is formd in the second semiconductor layer 654 b between the second source electrode 673 b and the second drain electrode 675 b.
A first one 663 a of the two first ohmic contact layers 663 a and 665 a is interposed between the first semiconductor layer 654 a and the first source electrode 673 a to decrease contact resistance between the first semiconductor layer 654 a and the first source electrode 673 a, and a second one 665 a of the two first ohmic contact layers 663 a and 665 a is interposed between the first semiconductor layer 654 a and the first drain electrode 675 a to decrease contact resistance between the first semiconductor layer 654 a and the first drain electrode 675 a. A first one 663 b of the two second ohmic contact layers 663 b and 665 b is interposed between the second semiconductor layer 654 b and the second source electrode 673 b to decrease contact resistance between the second semiconductor layer 654 b and the second source electrode 673 b, and a second one 665 b of the two second ohmic contact layers 663 b and 665 b is interposed between the second semiconductor layer 654 b and the second drain electrode 675 b to decrease contact resistance between the second semiconductor layer 654 b and the second drain electrode 675 b.
A data insulating layer 680 is formed on the gate insulating layer 640 to cover the first data lines 671 a and 671 b, the first and second source electrodes 673 a and 673 b, and the first and second drain electrodes 675 a and 675 b.
A first contact hole 685 a is formed on the first contact electrode 677 a through the data insulating layer 680. A second contact hole 685 b is formed on the second contact hole 677 b through the data insulating layer 680.
The pixel electrode 691 a and the common electrode 691 b are formed on the data insulating layer 680. The pixel electrode 691 a and the common electrode 691 b may include a transparent conductive material, a reflective material, etc. Examples of the transparent conductive material that may be used for the pixel electrode 691 a and the common electrode 691 b may include indium tin oxide (ITO), indium zinc oxide (IZO), carbon nano tube (CNT), etc. Examples of the reflective material that may be used for the pixel electrode 691 a and the common electrode 691 b may include aluminum, silver, chromium, an alloy thereof etc. These may be used alone or in a combination thereof.
The pixel electrode 691 a and the common electrode 691 b are formed on the data insulating layer 680. Alternatively, a transparent metal layer may be patterned to form the pixel electrode 691 a and the common electrode 691 b.
The pixel electrode 691 a makes contact with the first contact electrode 677 a.
The common electrode 691 b makes contact with the second contact electrode 677 b.
A contour formed by the pixel electrode 691 a and the common electrode 691 b may have a quadrangular shape.
The pixel electrode 691 a includes a first central extension electrically connected to the first drain electrode 675 a and extended in a horizontal direction.
The common electrode 691 b includes a second central extension electrically connected to the second drain electrode 675 b and extended in the horizontal direction. The second central extension surrounds the pixel region PX. Also, the second central extension may be overlapped with the first and second data lines 671 a and 671 b.
Different voltages having opposite polarities are applied to the first and second data lines 671 a and 671 b, so that parasite capacitance caused by the first and second data lines 671 a and 671 b may be removed.
For example, the pixel electrode 691 a includes a plurality of first branching parts extended from a lower portion of the pixel region PX toward an upper portion of the pixel region PX. The common electrode 691 b includes a plurality of second branching parts extended from the upper portion of the pixel region PX toward the lower portion of the pixel region PX. Thus, the first branching parts of the pixel electrode 691 a and the second branching parts of the common electrode 691 b alternate with each other to form a comb shape.
The pixel electrode 691 a is physically and electrically connected to the first drain electrode 675 a through the first contact hole 685 a to receive a data voltage from the first drain electrode 675 a. The common electrode 691 b is physically and electrically connected to the second drain electrode 675 b through the second contact hole 685 b to receive a data voltage from the second drain electrode 675 b. The pixel electrode 691 a, the common electrode 691 b and the liquid crystal layer 300 form a liquid crystal capacitor Clc. In the present embodiment, a voltage difference between the pixel electrode 691 a and the common electrode 691 b is maintained for a frame, although the first and second switching elements are turned off.
The first contact electrode 677 a of the first drain electrode 675 a electrically connected to the pixel electrode 691 a is overlapped with the storage electrode 633 with interposing the gate insulating layer 640 between the first contact electrode 677 a and the storage electrode 633 to form a first storage capacitor Csta. The second contact electrode 677 b of the second drain electrode 675 b electrically connected to the common electrode 691 b is overlapped with the storage electrode 633 with interposing the gate insulating layer 640 between the second contact electrode 677 b and the storage electrode 633 to form a second storage capacitor Cstb. The first and second storage capacitors Csta and Cstb maintain the voltage difference of the liquid crystal capacitor Clc.
The lower alignment layer 61 is formed on the lower base substrate 610 including the pixel electrode 691 a and the common electrodes 691 b to align liquid crystal molecules of the liquid crystal layer 300 in a vertical direction. Thus, the liquid crystal molecules of the liquid crystal layer 300 are aligned from the array substrate 600 toward the opposite substrate 200.
FIG. 11 is an equivalent circuit diagram illustrating the LCD device shown in FIG. 10.
Referring to FIGS. 10 and 11, the LCD device includes a plurality of pixels electrically connected to a plurality of signal lines Dj, Dj+1 and Gi.
In FIG. 10, the LCD device includes the array substrate 600, the opposite substrate 200 facing the array substrate 600, and the liquid crystal layer 300 interposed between the array substrate 600 and the opposite substrate 200.
The signal lines Dj, Dj+1 and Gi includes a gate line Gi, a first data line Dj and a second data line Dj+1. The gate line Gi transmits a gate signal (a scan signal). The first and second data lines Dj and Dj+1 transmit a data voltage. A plurality of the gate lines Gi is extended in a column direction, and is substantially parallel with each other. The first data line Dj and the second data line Dj+1 are extended in a row direction, and are substantially parallel with each other.
Voltages having opposite polarities are applied to the first data line Dj and the second data line Dj+1.
For example, the first and second data lines Dj and Dj+1 of FIG. 11 correspond to the first and second data lines 671 a and 671 b of FIG. 10 formed in the pixel region PX. The gate line Gi of FIG. 11 corresponds to the gate line 621 of FIG. 10. The first and second switching transistors Qa and Qb are electrically connected to the first and second data lines 671 a and 671 b, respectively.
Referring again to FIG. 11, the first and second data lines Dj and Dj+1 are electrically connected to the first and second switching elements Qa and Qb, respectively.
Referring again to FIGS. 10 and 11, the storage line 131 is overlapped with the pixel electrodes electrically connected to the first and second switching elements Qa and Qb to form the first and second storage capacitors Cst1 and Cst2.
The liquid crystal layer 300 in the pixel region PX functions as a dielectric material of the liquid crystal capacitor Clc. The liquid crystal capacitor Clc is formed by the pixel electrode, the common electrode and the liquid crystal layer 300.
The liquid crystal layer 300 has dielectric anisotropy. When the electric field is not applied to the liquid crystal layer 300, the liquid crystal molecules of the liquid crystal layer 300 are vertically aligned between the array substrate 600 and the opposite substrate 200.
Hereinafter, a method of manufacturing the array sustrate will be explained with reference to FIGS. 10 and 11.
The gate line 621 and the storage line 631 substantially parallel with each other are formed on the lower base substrate 610.
The first gate electrode 624 a, the second gate electrode 624 b and the storage electrode 633 are formed.
The gate insulating layer 640 is then formed on the lower base substrate 610.
A data metal layer including the first and second data lines 67 a and 671 b, the first and second drain electrodes 675 a and 675 b and the first and second source electrodes 673 a and 673 b is then formed.
The first and second data lines 671 a and 671 b are substantially parallel with each other.
The data insulating layer 680 is then formed.
The pixel electrode 691 a and the common electrodes 691 b are then formed. The common electrode 691 b is overlapped with the first and second data lines 671 a and 671 b.
The lower alignment layer 61 is then formed.
Different voltages having opposite polarities are alternately applied to the signal lines Dj, Dj+1 and Gi, so that a line inversion is performed in the LCD device in every frame.
According to the present embodiment the voltages having the different polarities are applied to the first and second data lines 671 a and 671 b, thereby preventing a parasite capacitance caused by the first and second data lines 671 a and 671 b. Thus, the voltages applied to the dta lines maintain constant level.
FIG. 12 is a plan view illustrating an LCD device in accordance with further still another embodiment of the present invention.
The LCD device of FIG. 12 is same as in FIGS. 1 to 4 except an array substrate 700. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 1 to 4 and any further explanation concerning the above elements will be omitted.
Also, the array substrate 700 of FIG. 12 is same as in FIG. 10 except a pixel electrode 791 a and a common electrode 791 b. Thus, the same reference numerals will be used for refer to the same or line parts as those described in FIG. 10 and any further explanation concerning the above elements will be omitted.
A data insulating layer 680 is formed on a lower base substrate 610. The pixel electrode 791 a and the common electrode 791 b are formed on the data insulating layer 680. The pixel electrode 791 a and the common electrode 791 b may include a transparent conductive material, a reflective material, etc. Examples of the transparent conductive material that may be used for the pixel electrode 791 a and the common electrode 791 b may include indium tin oxide (ITO), indium zinc oxide (IZO), carbon nano tube (CNT), etc. Examples of the reflective material that may be used for the pixel electrode 791 a and the common electrode 791 b may include aluminum, silver, chromium, an alloy thereof, etc. These may be used alone or in a combination thereof.
The pixel electrode 791 a and the common electrode 791 b are formed on the data insulating layer 780. In another embodiment, a transparent metal layer may be patterned to form the pixel electrodes 791 a and the common electrode 791 b.
The pixel electrode 791 a makes contact with the first contact electrode 677 a.
The common electrode 791 b makes contact with the second contact electrode 677 b.
A contour formed by the pixel electrode 791 a and the common electrode 791 b may have a quadrangular shape.
The pixel electrode 791 a includes a first central extension, a first main branching part and a first branching part. The first central extension is electrically connected to the first drain electrode 675 a and extended in a horizontal direction. The main first branching part crosses a center of the first central extension in a longitudinal direction. An upper portion of the first branching part is extended in a first diagonal direction, and a lower portion of the first branching part is extended in a second diagonal direction. The first diagonal direction forms an angle of about 45 degrees or about 225 degrees with respect to the gate line 621, and the second diagonal direction forms an angle of about 135 degrees or about 315 degrees with respect to the gate line 621.
The common electrode 791 b includes a second central extension, a second main branching part and a second branching part. The second central extension is electrically connected to the second drain electrode 675 b and extended in the horizontal direction. The second main branching part crosses a center of the second central extension in the longitudinal direction. An upper portion of the second branching part is extended in the first diagonal direction, and a lower portion of the second branching part is extended in the second diagonal direction. The first diagonal direction forms an angle of about 45 degrees or about 225 degrees with respect to the gate line 621, and the second diagonal direction forms an angle of about 135 degrees or about 315 degrees with respect to the gate line 621.
The second branching part may surround a pixel region, and may be overlapped with the first and second data lines 671 a and 671 b.
Thus, the first branching parts of the pixel electrode 791 a and the second branching parts of the common electrode 791 b alternate with each other to form a comb shape.
An equivalent circuit diagram of the LCD device shown in FIG. 12 is the same as the equivalent circuit diagram of FIG. 11. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIG. 11 and any further explanation concerning the above elements will be omitted.
The method of manufacturing the LCD device of FIG. 12 is the same as the method of manufacturing the LCD device of FIGS. 10 and 11. Thus, the same reference numerals will be used to refer to the same or like parts as those described in FIGS. 10 and 11 and any further explanation concerning the above elements will be omitted.
According to the present embodiment, the pixel electrode 791 a and the common electrode 791 b in the pixel region are extended in various directions, so that liquid crystal molecules of the liquid crystal layer 300 may be aligned in various directions,
According to some example embodiments of the present invention, the range of the pixel voltage difference is increased by the power lines receiving the various voltages, so that light transmittance of the array substrate may be increased.
Also, the storage capacitors are formed using the power lines, so that opening ratio of the array substrate is increased.
In addition, a parasite capacitor that may be generated in the data lines by overlapping between the data lines and the pixel electrodes receiving different voltages may be prevented, so that image display quality of the array substrate may be increased.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few example embodiments of the present invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific example embodiments disclosed, and that modifications to the disclosed example embodiments, as well as other example embodiments, are intended to be included within the scope of the appended claims. The present invention is defined by the following claims, with equivalents of the claims to be included therein.

Claims

1. An array substrate comprising:

a first switching element electrically connected to a first data line;

a second switching element electrically connected to a second data line adjacent to the first data line;

a third switching element electrically connected to a data power line interposed between the first and second data lines; and

a fourth switching element electrically connected to a gate power line receiving a voltage having different polarity from a voltage applied to the data power line.

2. The array substrate of claim 1, wherein voltages having opposite polarities are applied to the first and second data lines, respectively.

3. The array substrate of claim 1, further comprising:

a first gate line substantially parallel with the gate power line;

a first pixel electrode electrically connected to the first switching element;

a second pixel electrode electrically connected to the second switching element;

a first common electrode electrically connected to the third switching element; and

a second common electrode electrically connected to the fourth switching element, and

wherein the first pixel electrode and the first common electrode are disposed in a first pixel region, and the second pixel electrode and the second common electrode are disposed in a second pixel region adjacent to the first pixel region along the first gate line.

4. The array substrate of claim 3, further comprising:

a fifth switching element electrically connected to the first data line;

a sixth switching element electrically connected to the second data line;

a seventh switching element electrically connected to the gate power line; and

an eighth switching element electrically connected to the data power line.

5. The array substrate of claim 4, further comprising:

a first gate line extended in a direction substantantially parallel with the gate power line;

a third pixel electrode electrically connected to the fifth switching element;

a fourth pixel electrode electrically connected to the sixth switching element;

a third common electrode electrically connected to the seventh switching element; and

a fourth common electrode electrically connected to the eighth switching clement, and

wherein the third pixel electrode and the third common electrode are disposed in a third pixel region adjacent to the first pixel region along the first data line, and the fourth pixel electrode and the fourth common electrode are disposed in a fourth pixel region adjacent to the second pixel region along the first data line.

6. The array substrate of claim 5, further comprising:

a first gate line extended in a direction substantially parallel with the gate power line; and

a second gate line adjacent to the first gate line, and

wherein the first, second, third and fourth switching elements are electrically connected to the first gate line, and the fifth, sixth, seventh and eighth switching elements are electrically connected to the second gate line.

7. The array substrate of claim 5, wherein each of the first and second pixel electrodes and the first and second common electrodes comprises a plurality of branching parts, and

the branching part of the first pixel electrode alternates with the branching part of the first common electrode, and the brahcning part of the second pixel electrode alternates with the branching part of the second common electrode.

8. A method of manufacturing an array substrate, comprising:

forming a gate line and a gate power line substantially parallel with the gate line;

forming a first data line, a second data line and a data power line interposed between the first data line and the second data line; and

forming a first switching element electrically connected to the first data line and the gate line, a second switching element electrically connected to the second data line and the gate line, a third switching element electrically connected to the data power line and the gate line, and a fourth switching element electrically connected to the gate power line and the gate line, the gate power line receiving a voltage having different polarity from a voltage applied to the data power line.

9. The method of claim 8, further comprising forming a first pixel electrode electrically connected to the first switching element, a second pixel electrode electrically connected to the second switching element, a first common electrode electrically connected to the third switching element and a second common electrode electrically connected to the fourth switching element, and

wherein the first pixel electrode and the first common electrode are formed in a first pixel region, and the second pixel electrode and the second common electrode are formed in a second pixel region adjacent to the first pixel region along the gate line.

10. The method of claim 9, wherein the first second, third and fourth switching elements are formed by forming a fifth switching element electrically connected to the first data line, a sixth switching element electrically connected to the second data line, a seventh switching element electrically connected to the gate power line, and an eighth switching element electrically connected to the data power line.

11. An array substrate comprising:

a first pixel electrode overlapped with first and second power lines extended along a gate line, the first and second power lines receiving voltages having different polarities, respectively, the first pixel electrode being electrically connected to a first data line;

a second pixel electrode overlapped with the first and second power lines, the second pixel electrode being electrically connected to a second data line receiving a voltage having an opposite polarity to a voltage applied to the first data line;

a first common electrode overlapped with the first and second power lines, the first common electrode being electrically connected to the first power line; and

a second common electrode overlapped with the first and second power lines, the second common electrode being electrically connected to the second power line.

12. The array substrate of claim 11, wherein a capacitance of each of first storage capacitors formed by overlapping the first and second pixel electrodes and the first and second common electrodes with the first power line is substantially the same as a capacitance of each of second storae capacitors formed by overlapping the first and second pixel electrodes and the first and second common electrodes with the second power line.

13. The array substrate of claim 12, wherein the first common electrode is partially overlapped with the first and second data lines.

14. The array substrate of claim 13, further comprising a third data line adjacent to the second data line,

wherein the second common electrode is partially overlapped with the second and third data lines, and the first and second common electrodes are overlapped with first and second regions of the second data line, respectively.

15. The array substrate of claim 14, wherein the first region has substantially the same size as the second region.

16. The array substrate of claim 14, wherein the first and second pixel electrodes and the first and second common electrodes form a V-shape.

17. The array substrate of claim 16, wherein the first and second pixel electrodes comprise a plurality of first bending branches, and the first and second common electrodes comprise a plurality of second bending branches, and

wherein the first bending branches of the first pixel electrode alternate the second bending branches of the first common electrode, and the first bending branches of the second pixel electrode alternate the second bending branches of the second common electrode, and

wherein a distance between adjacent first and second bending branches adjacent to the first data line or the third data line is greater than a distance between adjacent first and second bending branches adjacent to a center between the first and second data lines and a center between the second and third data lines.

18. A method of manufacturing an array substrate, comprising:

forming a gate line, a first power line and a second power line, the gate line and the first and second power lines being substantially parallel with each other;

forming a first data line and a second data line adjacent to the first data line, the second data line receiving a voltage having opposite polarity to a voltage applied to the first data line, the first and second data lines being substantially parallel with each other; and

forming a first pixel electrode electrically connected to the first data line, a second pixel electrode electrically connected to the second data line, a first common electrode electrically connected to the first power line and a second common electrode electrically connected to the second power line, the first and second pixel electrodes and the first and second common electrodes being overlapped with the first and second power lines.

19. An array substrate comprising:

a pixel electrode electrically connected to a first data line; and

a common electrode electrically connected to a second data line receiving a voltage having opposite polarity to a voltage applied to the first data line, the common electrode being overlapped with the first and second data lines and being adjacent to the first data line.

20. The array substrate of claim 19, wherein an overlapped area between the common electrode and the first data line is substantially the same as an overlapped area between the common electrode and the second data line.

21. A method of manufacturing an array substrate, comprising:

forming a first data line and a second data line adjacent to the first data line, the second data line receiving a voltage having opposite polarity to a voltage applied to the first data line; and

forming a pixel electrode electrically connected to the first data line and a common electrode electrically connected to the second data line, the pixel electrode and the common electrode being overlapped with the first and second data lines.